一、 /sys/devices/system/cpu/cpu0 目录结构

/sys/devices/system/cpu/cpu0

Z91:/sys/devices/system/cpu/cpu0 # ls -al
ls -al
total 
drwxr-xr-x   root root     --09 : .
drwxr-xr-x  root root     --09 : ..
lrwxrwxrwx   root root     --09 : cpufreq -> ../cpufreq/policy
drwxr-xr-x   root root     --09 : cpuidle
lrwxrwxrwx   root root     --09 : of_node -> ../../../../firmware/de
vicetree/base/cpus/cpu@0
-rw-r--r--   root root  --09 : online
drwxr-xr-x   root root     --09 : power
lrwxrwxrwx   root root     --09 : subsystem -> ../../../../bus/cpu
drwxr-xr-x   root root     --09 : topology
-rw-r--r--   root root  --09 : uevent

二、重要信息获取

1. CPU 频率

cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq

cat cpuinfo_cur_freq

2.CPU 所支持的主频率列表（KHZ）

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_available_frequencies
cat scaling_available_frequencies

CPU 调频需要选择对应的档位，且参数不同机器该配置不同

3.CPU 策略policy

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_available_governors
cat scaling_available_governors
ondemand userspace powersave interactive performance sched

ondemand 表示使用内核提供的功能，可以动态调节频率
userspace 表示用户模式，在此模式下允许其他用户程序调节CPU频率
powersvae 表示省电模式，通常是在最低频率下运行
interactive ondemand相似,规则是“快升慢降”
performance 表示不降频，最高性能
sched 基于调度器的 CPU 调频机制

4.查看当前 CPU 的运行模式

通过echo命令，能够改变当前处理器的governor类型

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_governor
cat scaling_governor
sched

三、目录详情

1. cpufreq

主要获取 CPU 的频率、调频档位及策略等

http://blog.csdn.net/su749520/article/details/79023509

2. cpuidle

Z91:/sys/devices/system/cpu/cpu0/cpuidle # ls -al
ls -al
total 
drwxr-xr-x  root root  --09 : .
drwxr-xr-x  root root  --09 : ..
drwxr-xr-x  root root  --09 : driver
drwxr-xr-x  root root  --09 : state
drwxr-xr-x  root root  --09 : state1

2.1 cpuidle/driver

Z91:/sys/devices/system/cpu/cpu0/cpuidle/driver # ls -al
ls -al
total 
drwxr-xr-x  root root     --09 : .
drwxr-xr-x  root root     --09 : ..
-r--r--r--  root root  --09 : name

2.1.1 cpuidle/driver/name

Z91:/sys/devices/system/cpu/cpu0/cpuidle/driver # cat name
cat name
mt67xx_acao_cpuidle

2.2 cpuidle/state0

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # ls -al
ls -al
total 0
drwxr-xr-x 2 root root    0 2018-01-09 11:17 .
drwxr-xr-x 5 root root    0 2018-01-09 11:17 ..
-r--r--r-- 1 root root 4096 2018-01-09 11:17 desc
-rw-r--r-- 1 root root 4096 2018-01-09 11:17 disable
-r--r--r-- 1 root root 4096 2018-01-09 11:17 latency
-r--r--r-- 1 root root 4096 2018-01-09 11:17 name
-r--r--r-- 1 root root 4096 2018-01-09 11:17 power
-r--r--r-- 1 root root 4096 2018-01-09 11:17 residency
-r--r--r-- 1 root root 4096 2018-01-09 11:17 time
-r--r--r-- 1 root root 4096 2018-01-09 11:17 usage

2.2.2 cpuidle/state0/desc

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat desc
cat desc
wfi

2.2.2 cpuidle/state0/disable

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat disable
cat disable

2.2.2 cpuidle/state0/latency

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat latency
cat latency

2.2.2 cpuidle/state0/name

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat name
cat name
rgidle

2.2.2 cpuidle/state0/power

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat power
cat power

2.2.2 cpuidle/state0/residency

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat residency
cat residency

2.2.2 cpuidle/state0/usage

Z91:/sys/devices/system/cpu/cpu0/cpuidle/state0 # cat usage
cat usage

2.3 cpuidle/state1

目录结构和 state0 一致

3. of_node

Z91:/sys/devices/system/cpu/cpu0/of_node # ls -al
ls -al
total 0
drwxr-xr-x 2 root root  0 2018-01-10 14:56 .
drwxr-xr-x 8 root root  0 2018-01-10 14:56 ..
-r--r--r-- 1 root root  4 2018-01-10 14:56 clock-frequency
-r--r--r-- 1 root root 15 2018-01-10 14:56 compatible
-r--r--r-- 1 root root 28 2018-01-10 14:56 cpu-idle-states
-r--r--r-- 1 root root  8 2018-01-10 14:56 cpu-release-addr
-r--r--r-- 1 root root  4 2018-01-10 14:56 device_type
-r--r--r-- 1 root root  5 2018-01-10 14:56 enable-method
-r--r--r-- 1 root root  4 2018-01-10 14:56 linux,phandle
-r--r--r-- 1 root root  4 2018-01-10 14:56 name
-r--r--r-- 1 root root  4 2018-01-10 14:56 phandle
-r--r--r-- 1 root root  4 2018-01-10 14:56 reg

3.1 /of_node/clock-frequency

|Z91:/sys/devices/system/cpu/cpu0/of_node # cat clock-frequency
cat clock-frequency
w5?

3.2 /of_node/compatible

获取CPU架构信息

w5?Z91:/sys/devices/system/cpu/cpu0/of_node # cat compatible
cat compatible
arm,cortex-a53

3.3 /of_node/cpu-idle-states

cat 不出

3.4 /of_node/cpu-release-addr

cat 不出

3.5 /of_node/device_type

Z91:/sys/devices/system/cpu/cpu0/of_node # cat device_type
cat device_type
cpu

3.6 /of_node/enable-method

psci

3.7 /of_node/linux,phandle

cat 不出

3.8 /of_node/name

cpu

3.9 /of_node/phandle

cat 不出

3.10 /of_node/reg

cat 不出

4. online

查询结果如下

Z91:/sys/devices/system/cpu/cpu0 # cat online
cat online

表示当前 CPU 正在使用

5. power

Z91:/sys/devices/system/cpu/cpu0/power # ls -all
ls -all
total 0
drwxr-xr-x 2 root root    0 2018-01-09 11:17 .
drwxr-xr-x 5 root root    0 2018-01-09 11:17 ..
-rw-r--r-- 1 root root 4096 2018-01-09 11:17 autosuspend_delay_ms
-rw-r--r-- 1 root root 4096 2018-01-09 11:17 control
-r--r--r-- 1 root root 4096 2018-01-09 11:17 runtime_active_time
-r--r--r-- 1 root root 4096 2018-01-09 11:17 runtime_status
-r--r--r-- 1 root root 4096 2018-01-09 11:17 runtime_suspended_time

5.1 /power/autosuspend_delay_ms

cat 不出

Z91:/sys/devices/system/cpu/cpu0/power # cat autosuspend_delay_ms
cat autosuspend_delay_ms
/system/bin/sh: cat: autosuspend_delay_ms: I/O error

5.2 /power/control

cat control
auto

5.3 /power/runtime_active_time

cat runtime_active_time

5.4 /power/runtime_status

cat runtime_status
unsupported

5.5 /power/runtime_suspended_time

cat runtime_suspended_time

6. subsystem

Z91:/sys/devices/system/cpu/cpu0/subsystem # ls -all
ls -all
total 
drwxr-xr-x   root root     -- : .
drwxr-xr-x  root root     --09 : ..
drwxr-xr-x   root root     -- : devices
drwxr-xr-x   root root     -- : drivers
-rw-r--r--   root root  -- : drivers_autoprobe
--w-------   root root  -- : drivers_probe
--w-------   root root  -- : uevent

6.1 /subsystem/devices

Z91:/sys/devices/system/cpu/cpu0/subsystem/devices # ls -all
ls -all
total 
drwxr-xr-x  root root  -- : .
drwxr-xr-x  root root  -- : ..
lrwxrwxrwx  root root  -- : cpu -> ../../../devices/system/cpu/cp
u
lrwxrwxrwx  root root  -- : cpu1 -> ../../../devices/system/cpu/cp
u1
lrwxrwxrwx  root root  -- : cpu2 -> ../../../devices/system/cpu/cp
u2
lrwxrwxrwx  root root  -- : cpu3 -> ../../../devices/system/cpu/cp
u3

6.2 /subsystem/drivers

空文件夹

6.3 /subsystem/drivers_autoprobe

Z91:/sys/devices/system/cpu/cpu0/subsystem # cat drivers_autoprobe
cat drivers_autoprobe

6.4 /subsystem/drivers_probe

Z91:/sys/devices/system/cpu/cpu0/subsystem # cat drivers_probe
cat drivers_probe
/system/bin/sh: cat: drivers_probe: Permission denied

6.5 /subsystem/uevent

|Z91:/sys/devices/system/cpu/cpu0/subsystem # cat uevent
cat uevent
/system/bin/sh: cat: uevent: Permission denied

7. topology

Z91:/sys/devices/system/cpu/cpu0/topology # ls -all
ls -all
total 0
drwxr-xr-x 2 root root    0 2018-01-09 11:17 .
drwxr-xr-x 5 root root    0 2018-01-09 11:17 ..
-r--r--r-- 1 root root 4096 2018-01-09 11:17 core_id
-r--r--r-- 1 root root 4096 2018-01-09 11:17 core_siblings
-r--r--r-- 1 root root 4096 2018-01-09 11:17 core_siblings_list
-r--r--r-- 1 root root 4096 2018-01-09 11:17 physical_package_id
-r--r--r-- 1 root root 4096 2018-01-09 11:17 thread_siblings
-r--r--r-- 1 root root 4096 2018-01-09 11:17 thread_siblings_list

7.1 topology/core_id

cat core_id

7.2 topology/core_siblings

cat core_siblings
f

7.3 topology/core_siblings_list

cat core_siblings_list
-

7.4 topology/physical_package_id

cat physical_package_id

7.5 topology/thread_siblings

cat thread_siblings

7.6 topology/thread_siblings_list

cat thread_siblings_list

8. uevent

查询结果如下

Z91:/sys/devices/system/cpu/cpu0 # cat uevent
cat uevent
OF_NAME=cpu
OF_FULLNAME=/cpus/cpu@0
OF_TYPE=cpu
OF_COMPATIBLE_0=arm,cortex-a53
OF_COMPATIBLE_N=
MODALIAS=cpu:type:aarch64:feature:,,,,,,,,

Android 系统查看sys-devices-system-cpu-cpu0 目录结构一、 /sys/devices/system/cpu/cpu0 目录结构二、重要信息获取三、 目录详情

一、 /sys/devices/system/cpu/cpu0 目录结构

二、重要信息获取

1. CPU 频率

2.CPU 所支持的主频率列表（KHZ）

3.CPU 策略policy

4.查看当前 CPU 的运行模式

三、 目录详情

1. cpufreq

2. cpuidle

2.1 cpuidle/driver

2.1.1 cpuidle/driver/name

2.2 cpuidle/state0

2.3 cpuidle/state1

3. of_node

3.1 /of_node/clock-frequency

3.2 /of_node/compatible

3.3 /of_node/cpu-idle-states

3.4 /of_node/cpu-release-addr

3.5 /of_node/device_type

3.6 /of_node/enable-method

3.7 /of_node/linux,phandle

3.8 /of_node/name

3.9 /of_node/phandle

3.10 /of_node/reg

4. online

5. power

5.1 /power/autosuspend_delay_ms

5.2 /power/control

5.3 /power/runtime_active_time

5.4 /power/runtime_status

5.5 /power/runtime_suspended_time

6. subsystem

6.1 /subsystem/devices

6.2 /subsystem/drivers

6.3 /subsystem/drivers_autoprobe

6.4 /subsystem/drivers_probe

6.5 /subsystem/uevent

7. topology

7.1 topology/core_id

7.2 topology/core_siblings

7.3 topology/core_siblings_list

7.4 topology/physical_package_id

7.5 topology/thread_siblings

7.6 topology/thread_siblings_list

8. uevent

继续阅读

Android 系统查看sys-devices-system-cpu-cpu0 目录结构一、 /sys/devices/system/cpu/cpu0 目录结构二、重要信息获取三、目录详情

三、目录详情